The National Academy Of Clinical Biochemistry Presents LABORATORY MEDICINE PRACTICE GUIDELINES RECOMMENDATIONS FOR THE USE OF LABORATORY TESTS TO SUPPORT POISONED PATIENTS WHOArchived PRESENT TO THE EMERGENCY DEPARTMENT Laboratory Medicine Practice Guidelines Recommendations For The Use Of Laboratory Tests To Support Poisoned Patients Who Present To The Emergency Department EDITORS: Alan H.B. Wu, Ph.D., F.A.C.B. Charles McKay, M.D. The preparation of this revised monograph was achieved with the expert input of the editors, members of the guidelines committee, experts who submitted manuscripts for each section and many expert reviewers, who are listed at the end of the document. The material in this monograph represents the opinions of the editors and does not represent the official position of the National Academy of Clinical Biochemistry or any of the co-sponsoring organizations. The National Academy of Clinical Biochemistry is the official academy of the American Association of Clinical Chemistry. © 2003 by the American Association of Clinical Chemistry. Reproduced with permission. Presented at the American Association for Clinical Chemistry Annual Meeting, August 1-2, 2001. When citing this document, the AACC requests the following citation format: Wu AHB, Broussard LA, Hoffman RS, Kwong TC, McKay C, Moyer TP, Otten EM, Welch SL, Wax P. National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines: Recommendations for the Use of Laboratory Tests to Support the Impaired and Overdosed Patients from the Emergency Department. Clin Chem 2003;49:357-379. © 2005 by the National Academy of Clinical Biochemistry. Single copies for personal use may be printed from authorized Internet sources such as the NACB’s Home Page (www.nacb.org), provided it is printed in its entirety, including this notice. Printing of selected portions of the document is also permitted for personal use provided the user also prints and attaches the title page and cover pages to the selected reprint or otherwise clearly identifies the reprint as having been produced by the NACB. Otherwise, this document may not be reproduced in whole or in part, stored in a retrieval system, translated into another language, or transmitted in any form without express written permission of the National Academy of Clinical Biochemistry (NACB, 2101 L Street, N.W., Washington, DC 20037-1526). Permission will ordinarily be granted provided the logo of the NACB and the following notice appear prominently at the front of the document: Reproduced (translated) with permission of the National Academy of Clinical Biochemistry, Washington, DC Single or multiple copies may also be purchased from the NACB at the address above or by ordering through the Home Page (http://www.nacb.org/). Archived Printed by: Durik Advertising, Inc. 112 Granger View Court Franklin, TN 37064 phone: 615-794-8993 [email protected] Laboratory Medicine Practice Guidelines GUIDELINES COMMITTEE We gratefully acknowledge the following individuals who contributed the original manuscripts upon which this monograph is based: Larry A. Broussard, Ph.D., Department of Clinical Laboratory Sciences, Louisiana State University Health Sciences Center, New Orleans, LA USA Robert S. Hoffman, M.D., Department of Emergency Medicine, Bellevue Hospital Center, New York, NY USA Tai C. Kwong, Ph.D., Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY USA Charles McKay, M.D. Department of Emergency Medicine, Medical Toxicology, Hartford Hospital, Hartford, CT USA Thomas P. Moyer, Ph.D. Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN USA Edward M. Otten, M.D., Department of Emergency Medicine, University of Cincinnati Hospital, Cincinnati, OH USA Paul Wax, M.D., Department of Medical Toxicology Good Samaritan Regional Medical Center, Phoenix, AZ USA Shirley L. Welch, Ph.D., Department of Pathology, Kaiser Permanente Regional Laboratory, Clackamas, OR USA Alan H.B. Wu, Ph.D. Department of Laboratory Medicine, San Francisco General Hospital and the University of California, San Francisco, San Francisco, CA USA Archived 2 Laboratory Medicine Practice Guidelines TABLE OF CONTENTS Abstract . 4 Preface . 4 Introduction and Needs Assessment . 5 Section I. General Principles for Drug Testing to Support ED Toxicology . 7 A. Tier I Toxicology testing . 7 B. Assay turnaround times for tier I tests . 10 C. Tier II testing: comprehensive or broad-spectrum testing . 11 D. Selectivity of testing . 12 E. Drug panels by “toxidromes” . 12 F. Gastric Samples . 13 G. “Chain-of-custody” for clinical specimens . 14 Section II. Recommendations on Analytical and Reporting Issues for Drugs-of-Abuse Testing by Immunoassays . 15 A. Immunoassays . 15 B. Listing of cross-reacting substances on immunoassays . 15 C. Immunoassay cutoffs . 17 D. Inadequate spectrum of benzodiazepine detection by immunoassays . 17 E. Opiate vs opioid detection by immunoassay . 18 F. Immunoassays for amphetamines vs sympathomimetic drug class . 19 G. Confirmation of positive immunoassays . 20 Section III. Recommendations for Specific Analysis of Ethyl Alcohol and Other Toxic Alcohols . 21 A. Need for a breath alcohol quality-assurance/quality-control program . 21 B. Selection and validations of breath alcohol devices . 22 C. Reporting units for ethyl alcohol . 23 D. Assays for methanol and ethylene glycol . 24 E. Osmolality measurements for toxic alcohol surveillance . 26 F. Isopropyl alcohol, propylene glycol intoxication and acetoacetic acid . 26 Section IV. Recommendations on Laboratory Assays for Other Toxicants as Causes of Poisonings . 28 A. “Universal” acetaminophen and salicylate screening . 28 B. Cyanide and hydrogen sulfideArchived . 30 C. Anticoagulants . 31 D. Lead Poisoning . 31 E. Testing for iron toxicity . 32 F. Arsenic and mercury . 33 G. Broad-spectrum screening for trace elements and environmental pollutants . 34 H. Pesticides . 35 I. Inhalants . 35 J. Methemoglobinemia . 36 K. Regional toxicology centers . 37 References . 38 - 42 Appendix A Corporate Sponsors . 43 Appendix B Reviews and Commentators . 44 3 Laboratory Medicine Practice Guidelines Abstract Background: Exposure to drugs and toxins is a major cause for patients’ visits to the emergency department (ED). Methods: Recommendations for the use of clinical laboratory tests were prepared by an expert panel of analytical toxicologists and ED physicians specializing in clinical toxicology. These recommendations were posted on the world- wide-web and presented in open forum at several clinical chemistry and clinical toxicology meetings. Results: A menu of important stat serum and urine toxicology tests was prepared for clinical laboratories who provide clinical toxicology services. For drugs-of-abuse intoxication, most ED physicians do not rely on results of urine drug testing for emergent management decisions. This is in part because immunoassays, although rapid, have limitations in sensitivity and specificity and chromatographic assays, which are more definitive, are more labor-intensive. Ethyl alcohol is widely tested in the ED, and breath testing is a convenient procedure. Determinations made within the ED, however, require oversight by the clinical laboratory. Testing for toxic alcohols is needed, but rapid commercial assays are not available. The laboratory must provide stat assays for acetaminophen, salicylates, co-oximetry, cholinesterase, iron, and some therapeutic drugs, such as lithium and digoxin. Exposure to other heavy metals requires laboratory support for specimen collection but not for emergent testing. Conclusions: Improvements are needed for immunoassays, particularly for amphetamines, benzodiazepines, opioids, and tricyclic antidepressants. Assays for new drugs of abuse must also be developed to meet changing abuse patterns. As no clinical laboratory can provide services to meet all needs, the National Academy of Clinical Biochemistry Committee recommends establishment of regional centers for specialized toxicology testing. Preface This is the ninth in the series of Laboratory Medicine Practice Guidelines sponsored by the National Academy of Clinical Biochemistry (NACB).1 An expert committee of emergency department (ED) physicians and clinical laboratory medicine toxicologists was assembled and prepared recommendations on the use of clinical laboratory tests to support the diagnosis and management of the poisoned patient who presents to the ED. Excluded from these discussions were drug testing conducted for the workplace, forensic and medical examiner toxicology, athletic drug testing, and testing for various compliance programs (e.g., criminal justice, psychiatric, and physician health). Many of these other programs are guided by other recommendations and regulations, such as the Substance Abuse and Mental Health Services Administration, the American Academy of Forensic Sciences, and the International Olympic Committee. Recommendations for detection of drugs in pregnant women and newborns exposed during the intrauterine period are discussed in a previous NACB guidelines (1). Some of the recommendations contained here are directed specifically toward manufacturers of toxicology reagents. It is hoped that documentation of a clinical need for modified assays will encourage manufacturers to develop these new and improved assays. Archived These recommendations were presented in open forum at several meetings during the year 2001: a local clinical chemistry section meeting at the Royal